Synthesis and Characterization of Potassium Metal/Graphitic Carbon Nanofiber Intercalates

2008 ◽  
Vol 8 (4) ◽  
pp. 1942-1950
Author(s):  
Jason A. Michel ◽  
Vance S. Robinson ◽  
Liu Yang ◽  
Senthil Sambandam ◽  
Weijie Lu ◽  
...  
Keyword(s):  
Carbon Nanofiber ◽  
Thermionic Emission ◽  
Hydrogen Gas ◽  
Graphitic Carbon ◽  
Direct Reaction ◽  
X Ray Diffraction ◽  
Alkene Polymerization ◽  
Graphitic Carbon Nanofibers ◽  
Potassium Loading ◽  
Stage 1

Direct reaction of herringbone, platelet, or narrow, tubular herringbone graphitic carbon nanofibers (GCNFs) with molten potassium gives K/GCNF intercalates with stoichiometric control of potassium loading. Intercalate formation is confirmed by powder X-ray diffraction and micro-Raman spectroscopy. K/GCNF intercalates act as radical-anion alkene polymerization catalysts and reduce water with stoichiometric formation of hydrogen gas. Stage-1 K/narrow, tubular GCNF intercalate exhibits thermionic emission at 300 °C. Stage-1 K/herringbone GCNF intercalate is an excellent thermionic emitter having high thermal stability up to 1000 °C. K/GCNF intercalates have much reduced work functions of ca. 2.2 eV with localized emission showing a work function of 1.6 eV.

Graphitic carbon nanofiber growth from catalytic-metal organic frameworks & their electrochemical double layer properties

2017 ◽  
Vol 5 (48) ◽  
pp. 25338-25349 ◽  
Author(s):  
Parama Chakraborty Banerjee ◽  
Derrek E. Lobo ◽  
Tim Williams ◽  
Mahdokht Shaibani ◽  
Matthew R. Hill ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Double Layer ◽  
Carbon Nanofiber ◽  
Metal Organic Frameworks ◽  
Graphitic Carbon ◽  
Metal Organic ◽  
Catalytic Metal ◽  
Graphitic Carbon Nanofibers ◽  
Electrochemical Double Layer

Electrochemical utilization of catalyst particles significantly increases the capacitance of catalytic MOF-derived graphitic carbon-nanofibers.

Trifunctional Electrocatalytic Activities of Nitrogen‐Doped Graphitic Carbon Nanofibers Synthesized by Chemical Vapor Deposition

2021 ◽  
Vol 6 (20) ◽  
pp. 4867-4873
Author(s):  
Bhagyashri Todankar ◽  
Pradeep Desai ◽  
Ajinkya K. Ranade ◽  
Tharangattu N. Narayanan ◽  
Masaki Tanemura ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Nanofibers ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Graphitic Carbon ◽  
Nitrogen Doped ◽  
Graphitic Carbon Nanofibers

scholarly journals Synthesis and Compressibility of Novel Nickel Carbide at Pressures of Earth’s Outer Core

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 516
Author(s):  
Timofey Fedotenko ◽  
Saiana Khandarkhaeva ◽  
Leonid Dubrovinsky ◽  
Konstantin Glazyrin ◽  
Pavel Sedmak ◽  
...  
Keyword(s):  
Equation Of State ◽  
Outer Core ◽  
Direct Reaction ◽  
Volume Data ◽  
X Ray Diffraction ◽  
Nickel Carbide ◽  
Diamond Anvils ◽  
Group A ◽  
Diamond Anvil ◽  
Murnaghan Equation

We report the high-pressure synthesis and the equation of state (EOS) of a novel nickel carbide (Ni3C). It was synthesized in a diamond anvil cell at 184(5) GPa through a direct reaction of a nickel powder with carbon from the diamond anvils upon heating at 3500 (200) K. Ni3C has the cementite-type structure (Pnma space group, a = 4.519(2) Å, b = 5.801(2) Å, c = 4.009(3) Å), which was solved and refined based on in-situ synchrotron single-crystal X-ray diffraction. The pressure-volume data of Ni3C was obtained on decompression at room temperature and fitted to the 3rd order Burch-Murnaghan equation of state with the following parameters: V0 = 147.7(8) Å3, K0 = 157(10) GPa, and K0' = 7.8(6). Our results contribute to the understanding of the phase composition and properties of Earth’s outer core.

scholarly journals Catalytic Activity of Beta-Cyclodextrin-Gold Nanoparticles Network in Hydrogen Evolution Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Qui Quach ◽  
Erik Biehler ◽  
Ahmed Elzamzami ◽  
Clay Huff ◽  
Julia M. Long ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Gold Catalyst ◽  
Hydrogen Gas ◽  
Hydrolysis Reaction ◽  
X Ray Diffraction ◽  
Beta Cyclodextrin ◽  
Transmission Electron ◽  
Production Of Hydrogen ◽  
Climate Crisis

The current climate crisis warrants investigation into alternative fuel sources. The hydrolysis reaction of an aqueous hydride precursor, and the subsequent production of hydrogen gas, prove to be a viable option. A network of beta-cyclodextrin capped gold nanoparticles (BCD-AuNP) was synthesized and subsequently characterized by Powder X-Ray Diffraction (P-XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), and Ultraviolet-Visible Spectroscopy (UV-VIS) to confirm the presence of gold nanoparticles as well as their size of approximately 8 nm. The catalytic activity of the nanoparticles was tested in the hydrolysis reaction of sodium borohydride. The gold catalyst performed best at 303 K producing 1.377 mL min−1 mLcat−1 of hydrogen. The activation energy of the catalyst was calculated to be 54.7 kJ/mol. The catalyst resisted degradation in reusability trials, continuing to produce hydrogen gas in up to five trials.

scholarly journals Photodeposition of Ag Nanocrystals onto TiO2 Nanotube Platform for Enhanced Water Splitting and Hydrogen Gas Production

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Nur Aimi Jani ◽  
Choonyian Haw ◽  
Weesiong Chiu ◽  
Saadah Abdul Rahman ◽  
Poisim Khiew ◽  
...  
Keyword(s):  
Water Splitting ◽  
Gas Production ◽  
Hydrogen Gas ◽  
Current Work ◽  
Plasmonic Resonance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Production Of Hydrogen ◽  
Production Activity ◽  
Ag Ncs

Current work reports the study of Ag nanocrystals (NCs) decorated doubly anodized (DA) TiO2 nanotubes (NTs) thin film as an efficient photoelectrode material for water splitting and photocatalytic hydrogen gas production. DA process has been shown to be capable of producing less defective NTs and creating additional spacious gaps in between NT bundles to allow efficient and uniform integration of Ag NCs. By employing photoreduction method, Ag NCs can be deposited directly onto NTs, where the size and density of coverage can be maneuvered by merely varying the concentration of Ag precursors. Field emission scanning electron microscope (FESEM) images show that the Ag NCs with controllable size are homogeneously decorated onto the walls of NTs with random yet uniform distribution. X-ray diffraction (XRD) results confirm the formation of anatase TiO2 NTs and Ag NCs, which can be well indexed to standard patterns. The decoration of metallic Ag NCs onto the surface of NTs demonstrates a significant enhancement in the photoconversion efficiency as compared to that of pristine TiO2 NTs. Additionally, the as-prepared nanocomposite film also shows improved efficiency when used as a photocatalyst platform in the production of hydrogen gas. Such improvement in the performance of water splitting and photocatalytic hydrogen gas production activity can be credited to the surface plasmonic resonance of Ag NCs present on the surface of the NTs, which renders improved light absorption and better charge separation. The current work can serve as a model of study for designing more advanced nanoarchitecture photoelectrode for renewable energy application.

Hollow Graphitic Carbon Nanospheres Synthesized by Rapid Pyrolytic Carbonization

2021 ◽  
Vol 68 ◽  
pp. 1-16
Author(s):  
Cheng Zhang ◽  
Qing Shan Gao ◽  
Lu Yun Jiao ◽  
Laura Bogen ◽  
Nicole Forte ◽  
...  
Keyword(s):  
Rapid Heating ◽  
Conductivity Measurement ◽  
Graphitic Carbon ◽  
Bet Surface Area ◽  
Slow Heating ◽  
X Ray Diffraction ◽  
Carbon Nanospheres ◽  
X Ray ◽  
Carbonization Process ◽  
Transmission Electron

Hollow graphitic porous carbon nanosphere (CNS) materials are synthesized from polymerization of resorcinol (R) and formaldehyde (F) in the presence of templating iron polymeric complex (IPC), followed by carbonization treatment. The effect of rapid heating in the carbonization process is investigated for the formation of hollow graphitic carbon nanospheres. The resulting CNS from rapid heating was characterized for its structure and properties by transmission electron microscope (TEM), x-ray diffraction (XRD), Raman spectroscopy, bulk conductivity measurement and Brunauer-Emmett-Teller (BET) surface area. Hollow graphitic CNS with reduced degree of agglomeration is observed under rapid heating during the carbonization process when compared to the CNS synthesized using the standard slow heating approach. Key words: carbon nanosphere (CNS), rapid pyrolytic carbonization, agglomeration

A Simple High-Yield Synthesis of Gallium(I) Tetrachlorogallate(III) and the Reaction of Digallium Tetrachloride Tetrahydrofuran Solvate with 1,2-Diols

2001 ◽  
Vol 56 (4-5) ◽  
pp. 337-341 ◽  
Author(s):  
Eva S. Schmidt ◽  
Annette Schier ◽  
Norbert W. Mitzel ◽  
Hubert Schmidbaur
Keyword(s):  
Crystalline Phase ◽  
Hydrogen Gas ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Atoms ◽  
Gallium Hydride ◽  
Hydroxy Groups ◽  
Tetrahydrofuran Solution ◽  
Analogous Product

Abstract Gallium(I) tetrachlorogallate(III) Ga[GaCU] was prepared in quantitative yield by thermal de­composition of dichlorogallane [HGaCl2]2, which is readily available from Et3SiH and [GaCl3]2. The reaction of catechol with solutions of this gallium(I) tetrachlorogallate(III) in tetrahydrofuran leads to the evolution of hydrogen gas and affords a dinuclear gallium(III) complex with penta-coordinate metal atoms chelated and bridged by mono-deprotonated catechol ligands. In the crystalline phase tetrahydrofuran molecules are hydrogen-bonded to the hydroxy groups: [Ga(1,2 -OC6H4OH)Cl2(C4H8O)]2. The reaction with pinacol also gives hydrogen and the analogous product [Ga(OCMe2CMe2OH)Cl2(C4H8O)]2. The structures of the two compounds have been determined by X-ray diffraction. A mechanism of the new reaction has been proposed which involves oxidative addition of the diol to the solvate (THF)Cl2Ga-GaCl2(THF) present in the tetrahydrofuran solution to give a gallium hydride intermediate.

A new stacking variant of Na2Pt(OH)6

2018 ◽  
Vol 73 (11) ◽  
pp. 831-836 ◽  
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Oxygen Pressure ◽  
Title Compound ◽  
Structure Type ◽  
Direct Reaction ◽  
Solid Residue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edge Distance ◽  
Naoh Solution

AbstractA new stacking variant of sodium hexa-hydroxo platinate(IV), Na2Pt(OH)6, was synthesized and its structure elucidated through X-ray diffraction. The new polymorph was prepared by direct reaction of PtO2 with an excess of NaOH solution applying elevated oxygen pressure at 300°C. The structure consists of layers of edge sharing Pt(OH)6 and Na(OH)6 octahedra. These layers are separated by an edge-to-edge distance of ~2.4 Å. The packing of the hydroxide ions corresponds to the hcp sequence, the title compound thus may be regarded a cation ordered variant of the Brucite structure type. During heating above T~300°C all constitutional water is released, and anhydrous Na2PtO3 remains as the solid residue.

Rectifying Behavior of Aligned ZnO Nanorods on Mg0.3Zn0.7O Thin Film Template

2011 ◽  
Vol 364 ◽  
pp. 35-39 ◽  
Author(s):  
Salina Muhamad ◽  
Abu Bakar Suriani ◽  
Mohamad Hafiz Mamat ◽  
Rafidah Ahmad ◽  
Mohamad Rusop
Keyword(s):  
Thin Film ◽  
Zno Nanorods ◽  
Thermionic Emission ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Shape ◽  
Semiconductor Junction ◽  
Vertically Aligned ◽  
Scanning Electron

Rectifying behavior more than 3 orders of aligned zinc oxide (ZnO) nanorods grown on Mg0.3Zn0.7O thin film template using chemical bath deposition method was observed, giving a barrier height of 0.75 eV, and the ideality factor achieved was almost 6, which was analyzed using thermionic emission theory. Field emission scanning electron microscope (FESEM) images revealed that the grown ZnO was in hexagonal shape, uniformly distributed and in vertically aligned form. The crystallinity of the sample being studied using X-ray diffraction (XRD), where the highest peak was found at (002) phase, confirming that high crytallinity of ZnO was attained. The effect of metal/semiconductor junction between metal and aligned ZnO nanorods was discussed in further details.

Cobalt(II) chloride adducts with acetonitrile, propan-2-ol and tetrahydrofuran: considerations on nuclearity, reactivity and synthetic applications

2017 ◽  
Vol 73 (2) ◽  
pp. 104-114 ◽  
Author(s):  
Danilo Stinghen ◽  
André Luis Rüdiger ◽  
Siddhartha O. K. Giese ◽  
Giovana G. Nunes ◽  
Jaísa F. Soares ◽  
...  
Keyword(s):  
Single Molecule ◽  
Building Blocks ◽  
Direct Reaction ◽  
X Ray Diffraction ◽  
Single Molecule Magnets ◽  
X Ray ◽  
Ft Ir ◽  
Bond Network ◽  
Solvent Molecules ◽  
Intramolecular Hydrogen

High-spin cobalt(II) complexes are considered useful building blocks for the synthesis of single-molecule magnets (SMM) because of their intrinsic magnetic anisotropy. In this work, three new cobalt(II) chloride adducts with labile ligands have been synthesized from anhydrous CoCl2, to be subsequently employed as starting materials for heterobimetallic compounds. The products were characterized by elemental, spectroscopic (EPR and FT–IR) and single-crystal X-ray diffraction analyses.trans-Tetrakis(acetonitrile-κN)bis(tetrahydrofuran-κO)cobalt(II) bis[(acetonitrile-κN)trichloridocobaltate(II)], [Co(C2H3N)4(C4H8O)2][CoCl3(C2H3N)]2, (1), comprises mononuclear ions and contains both acetonitrile and tetrahydrofuran (thf) ligands, The coordination polymercatena-poly[[tetrakis(propan-2-ol-κO)cobalt(II)]-μ-chlorido-[dichloridocobalt(II)]-μ-chlorido], [Co2Cl4(C3H8O)4], (2′), was prepared by direct reaction between anhydrous CoCl2and propan-2-ol in an attempt to rationalize the formation of the CoCl2–alcohol adduct (2), probably CoCl2(HOiPr)m. The binuclear complex di-μ-chlorido-1:2κ4Cl:Cl-dichlorido-2κ2Cl-tetrakis(tetrahydrofuran-1κO)dicobalt(II), [Co2Cl4(C4H8O)4], (3), was obtained from (2) after recrystallization from tetrahydrofuran. All three products present cobalt(II) centres in both octahedral and tetrahedral environments, the former usually less distorted than the latter, regardless of the nature of the neutral ligand. Product (2′) is stabilized by an intramolecular hydrogen-bond network that appears to favour atransarrangement of the chloride ligands in the octahedral moiety; this differs from thecisdisposition found in (3). The expected easy displacement of the bound solvent molecules from the metal coordination sphere makes the three compounds good candidates for suitable starting materials in a number of synthetic applications.

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